<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="all" /> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <tr v-for="(item, index) in goodList" :key="index">
          <td>
            <input type="checkbox" name="" id="" v-model="item.checked" />
          </td>
          <td>{{ item.name }}</td>
          <td>{{ item.price }}</td>
          <td>
            <button @click="add(index)">+</button>
            <span>{{ item.num }}</span>
            <button @click="del(index)">-</button>
          </td>
          <td>{{ item.price * item.num }}</td>
          <td><button @click="delRemove(item.name)">删除</button></td>
        </tr>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:</td>
          <td colspan="5">{{ allNum }}</td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
export default {
  props: {
    goodList: {
      type: Array,
      required: true,
    },
  },
  computed: {
    //求选择的价格之和
    allNum() {
      let newList = this.goodList.filter((item) => item.checked);
      return newList.reduce((sum, item) => (sum += item.num * item.price), 0);
    },
    //全选
    all: {
      set(val) {
        this.goodList.forEach((obj) => (obj.checked = val));
      },
      get() {
        return this.goodList.every((item) => item.checked);
      },
    },
  },

  methods: {
    //添加数量
    add(index) {
      this.goodList[index].num++;
    },
    //减少数量
    del(index) {
      if (this.goodList[index].num === 0) return;
      this.goodList[index].num--;
    },
    //删除
    delRemove(name) {
      this.$emit("del", name);
    },
  },
};
</script>

<style>
</style>